Tag Archive for: Photosynthetic Bacteria

The primary means of nutrient uptake for cyanobacteria is oxygen-producing photosynthesis. Their ecological variety is astounding; they occupy a very wide range of lighted ecological niches in terrestrial, marine, and freshwater habitats. Despite this apparent metabolic consistency, they exhibit tremendous phylogenetic diversity. The fact that cyanobacteria have certain physiological and metabolic traits that are exclusively seen in prokaryotes significantly broadens this spectrum. The capacity to fix nitrogen in an aerobic manner under light is a special characteristic. Apart from Gonotheca species, all aerobic, nitrogen-fixing cyanobacteria—a structurally diverse group—produce heterocyst, the highly specialised cells that allow them to fix nitrogen efficiently in a fully aerobic environment by preventing the oxygen-sensitive enzyme nitrogenase from being inactivated quickly in vivo (Hazelton, 1978; Stanier and Cohen-Bazire, 1978; Stewart, Haystead, and Pearson, 1969). The same quantities of cyanobacteria could be isolated from freshwater using a technique using nutrient-saturated glass fibre filters, but the quantity of accompanying heterotrophic bacteria was reduced by 2- to 15-fold. a broad-spectrum antibiotic called imipenem. In comparison to some other Plactam antibiotics, the B-lactam antibiotic that inhibits peptidoglycan biosynthesis, was more effective at lowering the levels of heterotrophic bacterial contaminants associated with newly isolated cyanobacteria to a point that made it easier to grow axenic cyanobacterial cultures.